DEM Development and Precision Analysis in Two Local Areas of Antarctica, Using CryoSat-2 Altimetry Data

The Antarctic ice sheet plays a major role in studies of global climate change and sea-level rise, and digital elevation models (DEMs) are of great importance in geoscience studies of Antarctica. The interpolation method is one of the key factors to the accuracy of DEM. Five interpolation methods including inverse distance weighted, Kriging, radial basis functions, local polynomial, and Nearest Neighbor methods were used to develop DEMs for the Dome A area and the transect from Zhongshan station to Dome A using CryoSat-2 satellite altimetry data. A cross validation method was applied to evaluate the accuracy;the results indicate that Kriging method is the best of the five methods. Two DEMs for the two areas were generated by the Kriging interpolation method with CryoSat-2 data. The accuracy of two DEMs was assessed by GPS data from the 21st Chinese National Antarctic Research Expedition (CHINARE). The results show that the DEM of Dome A area has higher reliability with a bias of 1.248 m and standard deviation of 0.51 m. While in the steeper area in the Zhongshan station to Dome A transect, the accuracy of the DEM was low, the bias was 3.87 m and the standard deviation was 9.358 m.